System Identification of Plant Response for Optimal Cultivation in Greenhouses

Abstract Recently, greenhouse cultivations play an important role in agriculture. Environmental (climate) factors in the greenhouse are controlled based on PI or PID algorithm using a microcomputer. A lot of microcomputers are now in use in the field of the greenhouse cultivation. In order to realize the more effective control system of greenhouses, it is necessary to use the information based on physiological ecology which is so called speaking plant . For the first step to this purpose, we propose the new control system. That is the system composed of three computers:microcomputer(computer I) for DDC of environmental factors in the greenhouse, microcomputer(computer II) for estimation and decision of the control system based on both the environmental data and the plant responses, and data base(computer III) of physiological ecological responses and states which is remotely able to communicate with the computer II. This system needs the system identification. So, spectral analysis is examined for this purpose. As a result, plant responses are identified effectively in the transient state of the greenhouse.